May 3, 2008

Herbicide Exposure Leads to Higher Risk of Brain Cancer in Women

A recent study found that women who work regularly around weed killers could be at an increased risk of a certain type of brain cancer.

Initially, researchers found no added risk due to job-exposure to pesticides or herbicides.

However, researchers reported in the American Journal of Epidemiology after closer examination of the data collected from more than 1,400 U.S. adults, they found that women who had on-the-job exposure to the plant-killing chemicals were at twice the risk of developing meningioma than women who had never been exposed.

The study involved the cases of 462 glioma and 195 meningioma patients diagnosed between 1994 and 1998 in three US hospitals. Controls were 765 patients admitted to the same hospitals for nonmalignant conditions.

Researchers conducted interviews with patients to determine whether they had been exposed to herbicides during work.

There was no association between glioma and exposure to insecticides or herbicides, in men or women. Women who reported ever using herbicides had a significantly increased risk for meningioma compared with women who never used herbicides, Dr. Claudine M. Samanic of the National Cancer Institute in Bethesda, Maryland and her colleagues wrote.

However, they found only 33 women with brain cancer, and 71 without cancer, had ever been exposed to herbicides at work.

"Our finding that women exposed to herbicides experienced increased meningioma risk may be a chance finding, and our results should be interpreted cautiously," Samanic and her colleagues write.

There was no association between meningioma and herbicide or insecticide exposure among men, they added.

Of the 17 women with the highest herbicide exposure, most worked in restaurants or grocery stores, and were likely exposed by routinely handling produce contaminated with herbicides, the researchers note.

Samanic's team said their findings show the greater need to go beyond job title to clarify potential harm due to carcinogenic exposures within different occupations.